WO2018147113A1

WO2018147113A1 - Refrigerator

Info

Publication number: WO2018147113A1
Application number: PCT/JP2018/002740
Authority: WO
Inventors: 境　寿和; 克則堀井; 堀尾　好正; 文宣高見
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2017-02-07
Filing date: 2018-01-29
Publication date: 2018-08-16
Also published as: CN110249192A; JPWO2018147113A1

Abstract

This refrigerator includes a refrigeration cycle which has at least a compressor (19), an evaporator (20), an auxiliary cooler (46), a pre-stage condenser (21), a post-stage condenser (41), and a heating path (43). Also, the refrigerator has a flow passage-switching valve (40) connected to the downstream side of the pre-stage condenser (21). The flow passage-switching valve (40) switches a flow passage of a refrigerant toward the post-stage condenser (41) or the heating path (43). The refrigerator is configured such that when defrosting the evaporator (20), a high pressure refrigerant is supplied to the heating path (43) by switching the flow passage of the refrigerant toward the heating path (43), the evaporator (20) thermally connected to the heating path (43) is heated, and at the same time, the refrigerant that has dissipated heat in the heating path (43) is evaporated with the auxiliary cooler (46) connected to the downstream side of the heating path (43).

Description

refrigerator

This disclosure relates to a refrigerator that reduces the output of an electric heater for defrosting.

From the standpoint of energy saving, in household refrigerators, the flow of the refrigeration cycle is switched while the compressor is operated, and the output of the electric heater for defrosting is increased by supplying high pressure refrigerant to the evaporator and heating it. There is a refrigerator to reduce.

Hereinafter, a conventional refrigerator will be described with reference to the drawings.

FIG. 4 is a longitudinal sectional view of a conventional refrigerator, FIG. 5 is a configuration diagram of a refrigeration cycle of the conventional refrigerator, and FIG. 6 is a diagram illustrating operation control during defrosting of the conventional refrigerator.

As shown in FIG. 4, the conventional refrigerator 51 has a partition wall 52, a freezer compartment 53, and a refrigerator compartment 54. A cooler chamber 56 is provided between the freezer compartment bottom surface 55 that forms the bottom surface of the freezer compartment 53 and the partition wall 52. A main evaporator 57 is disposed in the cooler chamber 56. In the refrigerator 51, the cooling fan 58 is driven to supply the cold air generated in the main evaporator 57 to the freezer compartment 53 and to the refrigerator compartment 54 intermittently via the duct 59 and the damper 60. As shown in FIG. 5, the refrigerator 51 includes a compressor 61, a condenser 62, an auxiliary cooler 63, a two-way valve 64, a three-way valve 65, a capillary tube 66, and a capillary tube 67 as components constituting a refrigeration cycle. , Capillary tube 68, capillary tube 69, dryer 70, and defrosting pipe 71. Here, the defrosting pipe 71 is a refrigerant pipe that is thermally coupled to the main evaporator 57 and used to defrost the main evaporator 57. The defrosting pipe 71 is independent of the refrigerant pipe in the main evaporator 57 used when performing the cooling operation.

About the conventional refrigerator 51 comprised as mentioned above, the operation | movement is demonstrated below.

In the refrigerator 51, the cooling operation is performed by switching the flow path of the three-way valve 65 while operating the compressor 61 and supplying the high-pressure refrigerant compressed by the compressor 61 to the condenser 62. The refrigerant radiated by the condenser 62 is dried by the dryer 70, depressurized by the capillary tube 69 and the capillary tube 68, supplied to the main evaporator 57, evaporates, and then returns to the compressor 61. At this time, the two-way valve 64 can be closed to supply all the refrigerant to the main evaporator 57. Alternatively, the refrigerant can be distributed to both the main evaporator 57 and the auxiliary evaporator 63 by opening the two-way valve 64. Thereby, the refrigerating capacity at the time of cooling operation can be adjusted.

Next, with reference to FIG. 6, the operation control at the time of defrosting of the conventional refrigerator 51 is demonstrated.

6, the state “open” of the two-way valve 64 means that the flow path from the capillary tube 69 to the capillary tube 66 is opened. The state “blocking” of the two-way valve 64 means blocking the flow path from the capillary tube 69 to the capillary tube 66. The state “defrost” of the three-way valve 65 means that the flow path from the compressor 61 to the condenser 62 is closed and the flow path from the compressor 61 to the defrost pipe 71 is opened. The state “cooling” of the three-way valve 65 means that the flow path from the compressor 61 to the condenser 62 is opened and the flow path from the compressor 61 to the defrosting pipe 71 is closed.

In the section p in FIG. 6, a cooling operation is performed in which the refrigerant flows through both the main evaporator 57 and the auxiliary evaporator 63. In the section q, a cooling operation is performed in which the refrigerant flows only to the main evaporator 57. When the accumulated operation time of the compressor 61 reaches a predetermined time, the operation shifts to a defrosting operation in which the frost on the main evaporator 57 is heated and melted. In the section r, the flow path of the three-way valve 65 is switched to supply the high-pressure refrigerant compressed by the compressor 61 to the defrosting pipe 71. At this time, the main evaporator 57 is heated, and the refrigerant dissipated by the main evaporator 57 is decompressed by the capillary tube 67, supplied to the auxiliary evaporator 63 and evaporated, and then returned to the compressor 61. . Note that, during the defrosting operation, heating of the main evaporator 57 can be assisted using an electric heater (not shown). After the defrosting of the main evaporator 57 is completed, the cooling operation is restarted by switching the flow path of the three-way valve 65 and supplying the high-pressure refrigerant compressed by the compressor 61 to the condenser 62. In the section s in FIG. 6, a cooling operation is performed in which the refrigerant is allowed to flow only to the main evaporator 57. In the section t, a cooling operation is performed in which the refrigerant flows through both the main evaporator 57 and the auxiliary evaporator 63.

By the operation described above, the main evaporator 57 is heated using the high-pressure refrigerant of the refrigeration cycle, so that the electric energy of the defrost heater can be reduced, and the energy saving of the refrigerator 51 can be achieved. .

Furthermore, when the main evaporator 57 is heated using the high-pressure refrigerant of the refrigeration cycle, the temperature of the freezer compartment 53 can be suppressed by supplying the auxiliary evaporator 63 with the refrigerant.

However, in the configuration like the conventional refrigerator 51, the cooling operation and the defrosting operation are switched using the three-way valve 65 provided between the compressor 61 and the condenser 62. For this reason, the flow velocity of the refrigerant passing through the three-way valve 65 is fast, which causes the refrigerant flow noise to be generated. This is because, as a result of providing the three-way valve 65 on the upstream side of the condenser 62 in order to efficiently heat using the latent heat of condensation of the high-pressure refrigerant during the defrosting operation, not only during the defrosting operation, This is because the superheated steam having a low density passes through the three-way valve 65 even during the cooling operation. Further, immediately after switching from the cooling operation to the defrosting operation, a large amount of liquid refrigerant remains in the condenser 62. For this reason, the start-up of the defrosting operation is slow, a sufficient heating capacity cannot be obtained, and a reverse pressure is generated in which the pressure on the downstream side of the three-way valve 65 is higher than the pressure on the upstream side. It becomes a factor that durability decreases.

Therefore, when performing the defrosting operation, it efficiently heats using the latent heat of condensation of the high-pressure refrigerant, suppresses the flow rate of the refrigerant passing through the three-way valve 65, suppresses the generation of refrigerant flow noise, and starts from the cooling operation. It has been a challenge to quickly switch to defrosting operation.

JP-A-58-024774

The present disclosure has been made in view of the above-described conventional problems, and provides a refrigerator that realizes an efficient defrosting operation while suppressing generation of refrigerant flow noise.

Specifically, a refrigerator according to an example of the embodiment of the present disclosure includes at least a compressor, an evaporator, an auxiliary cooler, a pre-stage condenser, a post-stage condenser, and a refrigeration cycle having a heating path. In addition, the refrigerator according to an example of the embodiment of the present disclosure includes a flow path switching valve connected to the downstream side of the pre-stage condenser. The flow path switching valve switches the flow path of the high-pressure refrigerant from the front stage condenser to a rear stage condenser and a heating path connected in parallel with the rear stage condenser. The evaporator is thermally coupled to the heating path. In the refrigerator according to an example of the embodiment of the present disclosure, when the evaporator is defrosted, the flow path of the high-pressure refrigerant is switched to the heating path by the flow path switching valve, and the compressor is compressed by the compressor. The high-pressure refrigerant is supplied to the heating path, the evaporator is heated, and the heat dissipated in the heating path is evaporated by the auxiliary cooler connected to the downstream side of the heating path. Has been.

With such a configuration, when performing the defrosting operation, it is possible to efficiently heat using the latent heat of condensation of the high-pressure refrigerant, and it is possible to suppress the flow rate of the refrigerant passing through the branch path and suppress the generation of refrigerant flow noise. . Furthermore, with such a configuration, switching from the cooling operation to the defrosting operation can be performed quickly. Therefore, energy saving of the refrigerator can be achieved with such a configuration.

Moreover, the refrigerator according to an example of the embodiment of the present disclosure may include a heat exchange unit that thermally couples a part of the heating path and the compressor. Further, the refrigerator according to an example of the embodiment of the present disclosure is configured such that when the flow path switching valve is opened to the heating path side and the evaporator is defrosted, the evaporator is heated using waste heat of the compressor. It may be configured to be heated.

With such a configuration, when performing the defrosting operation, the waste heat of the compressor can be used to increase the enthalpy of the high-pressure refrigerant so that it can be heated more efficiently, and energy saving of the refrigerator can be achieved. Can do.

Further, the refrigerator according to an example of the embodiment of the present disclosure is cooled in advance until immediately before the evaporator is defrosted, and the flow path of the high-pressure refrigerant is condensed by the flow path switching valve without stopping the compressor. The evaporator may be defrosted by switching from the evaporator to the heating path.

With such a configuration, it is possible to improve the heat exchange efficiency with the compressor by suppressing an increase in the internal temperature during defrosting and increasing the temperature of the compressor during the cooling operation to be performed in advance. .

FIG. 1 is a longitudinal sectional view of a refrigerator according to an example of an embodiment of the present disclosure. FIG. 2 is a cycle configuration diagram of a refrigerator according to an example of the embodiment of the present disclosure. Drawing 3 is a figure showing control at the time of defrosting of a refrigerator by an example of an embodiment of this indication. FIG. 4 is a longitudinal sectional view of a conventional refrigerator. FIG. 5 is a cycle configuration diagram of a conventional refrigerator. FIG. 6 is a diagram illustrating the operation of a flow path switching valve of a conventional refrigerator.

Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings. Note that the present disclosure is not limited to the following embodiments.

(Embodiment)
FIG. 1 is a longitudinal sectional view of a refrigerator according to an example of an embodiment of the present disclosure. FIG. 2 is a diagram illustrating a cycle configuration of a refrigerator according to an example of the embodiment of the present disclosure. Drawing 3 is a figure showing control at the time of defrosting of a refrigerator by an example of an embodiment of this indication.

As shown in FIG. 1 and FIG. 2, the refrigerator 11 is provided with a housing 12, a door 13, legs 14 that support the housing 12, a lower machine room 15 provided at the lower portion of the housing 12, and an upper portion of the housing 12. And a freezer compartment 18 disposed at the lower part of the casing 12. The refrigerator 11 is housed in a compressor 19 housed in the upper machine room 16, an evaporator 20 housed on the back side of the freezer room 18, and a lower machine room 15 as components constituting the refrigeration cycle. The former stage condenser 21 is provided. In addition, the refrigerator 11 is attached to the partition wall 22 that partitions the lower machine room 15, the fan 23 that air-cools the upstream condenser 21, the evaporating dish 24 installed on the leeward side of the partition wall 22, and the lower machine room 15 The bottom plate 25 is provided.

Here, the compressor 19 is a variable speed compressor, and is configured to use a six-stage rotational speed selected from 20 to 80 rps. This is because the refrigerating capacity is adjusted by switching the rotational speed of the compressor 19 to six stages from low speed to high speed while avoiding resonance of piping and the like. Further, the compressor 19 is configured to operate at a low speed at the time of start-up, and to increase the speed as the operation time for cooling the refrigerator compartment 17 or the freezer compartment 18 becomes longer. This is because the most efficient low speed is mainly used, and an appropriate relatively high rotational speed is used against an increase in the load of the refrigerator compartment 17 or the freezer compartment 18 due to high outside air temperature and door opening / closing. . At this time, the rotation speed of the compressor 19 is controlled independently of the cooling operation mode of the refrigerator 11. In addition, the rotation speed at the time of starting the refrigeration cooling mode with a high evaporation temperature and a relatively large refrigerating capacity may be set lower than in the refrigeration cooling mode. The refrigerator 11 may be configured to adjust the refrigeration capacity by decelerating the compressor 19 as the temperature of the refrigerator compartment 17 or the freezer compartment 18 decreases.

In addition, a plurality of air intakes 26 provided in the bottom plate 25, an exhaust port 27 provided on the back side of the lower machine room 15, and a communication air passage 28 connecting the exhaust port 27 of the lower machine room 15 and the upper machine room 16 are provided. is doing. Here, the lower machine chamber 15 is divided into two chambers by a partition wall 22, a pre-stage condenser 21 is disposed on the windward side of the fan 23, and an evaporating dish 24 is disposed on the leeward side.

The refrigerator 11 includes a dryer 38, a flow path switching valve 40, a rear condenser 41, a throttle 42, a heating path 43, a heat exchange unit 44, a heating side throttle 45, and an auxiliary cooler as components constituting a refrigeration cycle. 46 and a heating side suction pipe 47. The dryer 38 is located on the downstream side of the pre-stage condenser 21 and dries the circulating refrigerant. The flow path switching valve 40 is located on the downstream side of the dryer 38 and controls the flow of the refrigerant. The rear-stage condenser 41 is located downstream of the flow path switching valve 40 and is thermally coupled to the outer surface of the housing 12 around the opening of the freezer compartment 18. The throttle 42 connects the post-stage condenser 41 and the evaporator 20. The heating path 43 is connected to the downstream side of the flow path switching valve 40 in parallel with the post-stage condenser 41. The heat exchange unit 44 is thermally coupled to the compressor 19 in the heating path 43. The heating side throttle 45, the auxiliary cooler 46, and the heating side suction pipe 47 are connected to the downstream side of the heating path 43. Here, a part of the heating path 43 between the heat exchanging unit 44 and the heating side throttle 45 is thermally coupled to the evaporator 20. Further, a part of the heating path 43 between the heat exchanging portion 44 and the heating side throttle 45 is independent of the refrigerant pipe that supplies the refrigerant from the throttle 42 to the evaporator 20. Further, the refrigerant supplied from the throttle 42 to the evaporator 20 returns to the compressor 19 via the suction pipe 48, while the refrigerant supplied from the heating side throttle 45 to the auxiliary cooler 46 is heated to the suction side. It returns to the compressor 19 via the pipe 47.

Moreover, the flow path switching valve 40 can control the opening and closing of the single refrigerant flow in each of the post-stage condenser 41 and the heating path 43. Usually, the flow path switching valve 40 maintains the flow path from the pre-stage condenser 21 to the post-stage condenser 41 in an open state and maintains the flow path from the pre-stage condenser 21 to the heating path 43 in a closed state. ing. The flow path switching valve 40 opens and closes the flow path only during defrosting described later.

Further, as shown in FIG. 1, the refrigerator 11 has an evaporator fan 30 that supplies cold air generated in the evaporator 20 to the refrigerator compartment 17 and the freezer compartment 18, and a freezer that blocks cold air supplied to the freezer compartment 18. It has a room damper 31, a refrigerator compartment damper 32 that blocks cold air supplied to the refrigerator compartment 17, and a duct 33 that supplies cold air to the refrigerator compartment 17. In addition, the refrigerator 11 includes a freezer temperature sensor 34 that detects the temperature of the freezer 18, a refrigerator temperature sensor 35 that detects the temperature of the refrigerator 17, and a defrost temperature sensor 36 that detects the temperature of the evaporator 20. Have. Here, the duct 33 is formed along the wall surface where the refrigerator compartment 17 and the upper machine room 16 are adjacent to each other. A part of the cold air passing through the duct 33 is discharged from the vicinity of the center of the refrigerator compartment 17. Most of the cool air passing through the duct 33 is discharged from the upper part of the refrigerator compartment 17 after the upper machine room 16 passes while cooling the adjacent wall surface.

The operation of the refrigerator 11 of the present embodiment configured as described above will be described below, but the same components as those in the conventional example are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the cooling stop state in which the fan 23, the compressor 19 and the evaporator fan 30 are all stopped (hereinafter, this operation is referred to as "OFF mode"), the temperature detected by the freezer temperature sensor 34 is a predetermined value. When the temperature rises to the FCC_ON temperature or the temperature detected by the cold room temperature sensor 35 rises to a predetermined PCC_ON temperature, the freezer damper 31 is closed and the cold room damper 32 is opened. 19. The fan 23 and the evaporator fan 30 are driven (hereinafter, this operation is referred to as “refrigeration cooling mode”).

In the refrigerated cooling mode, the fan 23 is driven, the front condenser 21 side of the lower machine chamber 15 partitioned by the partition wall 22 becomes negative pressure, external air is sucked from the plurality of intake ports 26, and the evaporating dish 24 side is positive pressure. Thus, the air in the lower machine chamber 15 is discharged to the outside from the plurality of discharge ports 27.

On the other hand, the refrigerant discharged from the compressor 19 is condensed while leaving a part of the gas while exchanging heat with the outside air in the pre-stage condenser 21, and then moisture is removed by the dryer 38, via the flow path switching valve 40. It is supplied to the latter stage condenser 41 (see FIG. 2). The refrigerant that has passed through the rear-stage condenser 41 is condensed by radiating heat through the housing 12 while warming the opening of the freezer compartment 18, then depressurized by the throttle 42, evaporated by the evaporator 20, and then stored in the refrigerator compartment 17. While refrigerating the refrigeration chamber 17 by exchanging heat with the internal air, the refrigerant is returned to the compressor 19 as a gaseous refrigerant through the suction pipe 48.

During the refrigeration cooling mode, when the temperature detected by the freezer temperature sensor 34 falls to a predetermined FCC_OFF temperature and the temperature detected by the refrigerator temperature sensor 35 falls to a predetermined PCC_OFF temperature, the mode changes to the OFF mode. .

In addition, when the temperature detected by the freezer temperature sensor 34 is higher than a predetermined FCC_OFF temperature and the temperature detected by the refrigerator temperature sensor 35 falls to a predetermined PCC_OFF temperature during the refrigerating / cooling mode, the freezer The compressor 19, the fan 23, and the evaporator fan 30 are driven with the chamber damper 31 open and the refrigerator compartment damper 32 closed. Hereinafter, by operating the refrigeration cycle in the same manner as in the refrigeration cooling mode, the freezing chamber 18 is cooled by exchanging heat between the inside air of the freezing chamber 18 and the evaporator 20 (hereinafter, this operation is referred to as “refrigeration cooling mode”). ).

If the temperature detected by the freezer temperature sensor 34 falls to a predetermined FCC_OFF temperature and the temperature detected by the refrigerator temperature sensor 35 indicates the predetermined value or more of the PCC_ON temperature during the freezing / cooling mode, the refrigerating / cooling mode is entered. Transition.

In addition, when the temperature detected by the freezer temperature sensor 34 falls to a predetermined FCC_OFF temperature and the temperature detected by the refrigerator temperature sensor 35 is lower than the predetermined PCC_ON temperature during the freezing / cooling mode, Transition to OFF mode.

Here, the control at the time of defrosting of the refrigerator 11 of this Embodiment is demonstrated.

In FIG. 3, the state “open / close” of the flow path switching valve 40 opens the flow path from the pre-stage condenser 21 to the post-stage condenser 41 and closes the flow path from the pre-stage condenser 21 to the heating path 43. Means that. Further, the state “closed / opened” of the flow path switching valve 40 is to close the flow path from the pre-stage condenser 21 to the post-stage condenser 41 and open the flow path from the pre-stage condenser 21 to the heating path 43. Means. The state “closed / closed” of the flow path switching valve 40 means that the flow path from the pre-stage condenser 21 to the post-stage condenser 41 is closed and the flow path from the pre-stage condenser 21 to the heating path 43 is closed. To do.

When the accumulated operation time of the compressor 19 reaches a predetermined time, the operation proceeds to a defrosting mode in which the frost on the evaporator 20 is heated and melted. In the section “a” of the defrost mode, first, the freezer compartment 18 is cooled for a predetermined time in the same manner as in the freezer cooling mode in order to suppress the temperature rise of the freezer compartment 18. Next, in the section b, by closing the flow path switching valve 40 while operating the compressor 19, the flow path from the front stage condenser 21 to the rear stage condenser 41 and the heating path 43 is closed. The refrigerant that stays in the rear-stage condenser 41, the evaporator 20, and the heating path 43 is collected in the front-stage condenser 21.

In the section c, the flow path switching valve 40 is switched while the operation of the compressor 19 is continued, and the flow path from the pre-stage condenser 21 to the heating path 43 is opened. The high-pressure refrigerant recovered in the pre-stage condenser 21 is supplied to the evaporator 20. At this time, the high-pressure refrigerant is heated by the waste heat of the compressor 19 during operation in the heat exchanging unit 44 provided in the heating path 43, and the dryness increases. Therefore, compared with the case where the high-pressure refrigerant is supplied to the evaporator 20 without being heated in the heat exchanging unit 44 in the section c, the high-pressure refrigerant having increased enthalpy and the evaporator 20 can be heat-exchanged. A quantity of heat can be added to the evaporator 20. Then, the refrigerant condensed by heat exchange with the evaporator 20 at the end of the heating path 43 is depressurized by the heating side throttle 45 and then evaporated by the auxiliary cooler 46, and the air in the freezer compartment 18. While cooling the freezer compartment 18 through heat exchange, the refrigerant is returned to the compressor 19 as a gaseous refrigerant through the heating side suction pipe 47.

Next, in the section d, the defrosting heater (not shown) attached to the evaporator 20 is energized to complete the defrosting. Completion of defrosting is determined when the defrosting temperature sensor 36 reaches a predetermined temperature. In section e, the flow path switching valve 40 is switched to close the flow path from the pre-stage condenser 21 to the heating path 43, and the flow path from the pre-stage condenser 21 to the post-stage condenser 41 is opened. Normal operation is resumed.

As described above, in the refrigerator 11 according to an example of the embodiment of the present disclosure, the flow path switching valve 40 is disposed between the front-stage condenser 21 and the rear-stage condenser 41, and the path through which the refrigerant in the two-phase region flows is provided. It is comprised so that it can branch and can switch a cooling operation and a defrost operation. With such a configuration, when performing the defrosting operation, it is possible to efficiently heat using the condensation latent heat of the high-pressure refrigerant, and it is possible to suppress the flow rate of the refrigerant passing through the branch path and suppress the generation of refrigerant flow noise. . Further, with such a configuration, switching from the cooling operation to the defrosting operation can be performed quickly.

In addition, in this Embodiment, although the auxiliary cooler 46 showed the aspect directly heat-exchanged with the air in the freezer compartment 18, the cool storage agent thermally couple | bonded with the auxiliary cooler 46 may be provided. Thus, after the cooling heat generated in the auxiliary cooler 46 during the defrosting operation is temporarily stored in the regenerator, it can be used little by little for cooling the air in the freezer compartment 18, and the auxiliary cooler 46 and the freezer compartment 18 can be used. It is possible to reduce the size by reducing the surface area for heat exchange with the air inside.

Furthermore, the refrigerator 11 according to the present embodiment includes a heat exchange unit 44 that thermally couples a part of the heating path 43 and the compressor 19. With this configuration, when the flow path switching valve 40 is opened to the heating path 43 side and the evaporator 20 is defrosted, a part of the precondenser 21 is condensed using the waste heat of the compressor 19. After improving the dryness of the high-pressure refrigerant, the evaporator 20 is heated to increase the enthalpy of the high-pressure refrigerant using the waste heat of the compressor 19 during the defrosting operation, thereby further improving the efficiency. Can warm well. Thereby, energy saving of a refrigerator can be achieved.

In the present embodiment, the refrigerant temperature of the heat exchanging unit 44 and the refrigerant temperature of the pre-stage condenser 21 are substantially the same, but the channel resistance in the heating path 43 on the upstream side of the heat exchanging unit 44. May be provided to lower the refrigerant temperature in the heat exchanging section 44 than the pre-stage condenser 21. Thereby, the heat exchange efficiency with the compressor 19 can be improved.

Furthermore, the refrigerator according to the present embodiment performs a cooling operation in advance until immediately before the evaporator 20 is defrosted, and the flow path of the high-pressure refrigerant from the rear-stage condenser 41 by the flow path switching valve 40 without stopping the compressor 19. By switching to the heating path 43, the evaporator 20 is defrosted, so that an increase in the internal temperature of the refrigerator compartment 17 and the freezer compartment 18 during the defrosting can be suppressed. Moreover, the heat exchange efficiency with the compressor 19 can be improved by raising the temperature of the compressor 19 during the cooling operation performed in advance.

In addition, the refrigerator 11 of this Embodiment is comprised so that the evaporator fan 30 may be stopped during the defrost operation of the area c and the area d, and the evaporator 20 may not be cooled with the cold air in the freezer compartment 18. . However, immediately after switching to the defrosting operation, the evaporator fan 30 may be driven for a predetermined time to exchange heat between the cold air in the refrigerator compartment 17 or the freezer compartment 18 and the evaporator 20. As a result, immediately after switching to the defrosting operation, the refrigerant stored in the rear condenser 41 is supplied to the evaporator 20 and the evaporator 20 is cooled, so that the inside of the refrigerator compartment 17 or the freezer compartment 18 is cooled. The evaporator 20 can be heated by exchanging heat between the cold air and the evaporator 20.

As described above, the present disclosure can reduce the output of the electric heater for defrosting by heating the high-pressure refrigerant in the refrigeration cycle to the evaporator by using the waste heat of the compressor. Provide a refrigerator. Therefore, the present invention can be applied to refrigerators for home use and commercial use, and other frozen and refrigerated products.

DESCRIPTION OF SYMBOLS 11 Refrigerator 12 Case 13 Door 14 Leg 15 Lower machine room 16 Upper machine room 17 Refrigeration room 18 Freezing room 19 Compressor 20 Evaporator 21 Pre-stage condenser 22 Bulkhead 23 Fan 24 Evaporating dish 25 Bottom plate 26 Inlet 27 Outlet 28 Ventilation path 30 Evaporator fan 31 Freezer compartment damper 32 Refrigeration compartment damper 33 Duct 34 Freezer compartment temperature sensor 35 Refrigerator compartment temperature sensor 36 Defrost temperature sensor 40 Flow path switching valve 41 Rear stage condenser 42 Restriction 43 Heating path 44 Heat exchange section 45 Heating side throttle 46 Auxiliary cooler 47 Heating side suction pipe 48 Suction pipe

Claims

At least a compressor, an evaporator, an auxiliary cooler, a pre-stage condenser, a post-stage condenser, and a refrigeration cycle having a heating path,
A flow path switching valve which is connected to the downstream side of the front stage condenser and switches the flow path of the high-pressure refrigerant from the front stage condenser to the rear stage condenser and the heating path connected in parallel with the rear stage condenser. Have
The evaporator is thermally coupled to the heating path;
When defrosting the evaporator, the flow path switching valve is switched to the heating path, and the high-pressure refrigerant from the pre-stage condenser compressed by the compressor is supplied to the heating path, While warming the evaporator,
The refrigerator comprised so that the refrigerant | coolant thermally radiated in the said heating path | route may be evaporated with the said auxiliary cooler connected to the downstream of the said heating path | route.
A heat exchanging unit that thermally couples a part of the heating path and the compressor, and opens the flow path switching valve to the heating path side to defrost the evaporator. The refrigerator according to claim 1, wherein the evaporator is heated using waste heat of the machine.
The cooling operation is performed in advance until immediately before the evaporator is defrosted, and the flow path switching valve is switched from the subsequent condenser to the heating path without stopping the compressor to remove the evaporator. The refrigerator according to claim 2 configured to be frosted.